Coral Bleaching

Researchers from Hawaiian Islands Humpback Whale National Marine Sanctuary and Papahānaumokuākea Marine National Monument recently teamed up to conduct a survey of the coral reefs throughout the Main Hawaiian Islands, which are currently being affected by a mass bleaching event. Coral bleaching occurs when corals are stressed -- in this case, by warm ocean water -- and expel the symbiotic algae that they need to survive. Together with researchers from the University of Hawaii Sea Grant College Program, the NOAA Hawaiian Islands Sentinel Site Cooperative, NOAA Fisheries Service Coral Reef Ecosystem Program, and the State of Hawai'i, sanctuary researchers collected data that will help them evaluate where bleaching is occurring and which species are most affected. Check out our video to learn more! #EarthIsBlue #CoralsWeek


This year, the Hawaiian Islands have experienced mass coral bleaching due to a large warm water event. So we’re here to study the coral reefs to survey which areas are bleached and which areas are experiencing other disease outbreaks.

The kind of data we’re collecting are data on species, data on the extent of bleaching and the extent of disease. So the amount of the colony that is experiencing bleaching and disease, how bad that bleaching is.

Collecting this kind of data is really important because it can help us answer questions about where bleaching is occurring and which species are being most impacted. And this kind of information helps us make better decisions about how to manage our coral reefs, which are a really important resource here in the Hawaiian Islands.

We did see plenty of bleaching down there on this particular dive, throughout almost every species that we surveyed, and also in both small and large colonies.

Thanks for joining us on our dive! Check some more of our pictures and videos on